The presently existing shuttles for automated warehouse cranes have various deficiencies.
One shuttle concept utilizes a magnetic means to latch onto material handling pallet or pan for loading and offloading. This concept is undesirable for several reasons. If the weight of the load is greater than the holding strength of the magnets then the material cannot be moved. To increase the weight capabilities of this type of shuttle latch it would be required to construct the unit with excessive mass thereby limiting the support structure height to stiffen the crane, tracks and etc. Another problem exists; only items that can be stored are items not adversely affected by the magnets.
Another commonly known shuttle concept utilizes a horizontal deflecting hook or rod which extends toward the material handling pallet or pan then rotates 90.degree. to catch a lip on the handling means. This concept is further limited in the amount of weight it can handle due to the sensitive nature of its operating mechanism as well as the construction of its pallets or pan material handling means, namely, the handling means comprises a separate material holding portion and a lip portion for engagement of the deflecting hook or rod that is separate and generally attached to the holding portion by welding or bolting that fails after prolonged use.
Still another shuttle concept utilizes spaced apart successively operable pairs of pins to sequentially move the material handling container on or off the shuttle. This concept like the others mentioned is considerably complicated in operation and construction which results in considerable down time for repair and synchronization.
These and various other problems were not satisfactorily resolved until the emergence of the instant invention.